San Francisco transportation planners are proposing to designate three zones in the city’s gay Castro district to be used during a portion of the day by commuter shuttle buses.

The proposal is part of the 18-month-long citywide pilot project that began in August to deal with the numerous buses that transport tech company employees from various neighborhoods throughout the city to their employers’ corporate campuses on the Peninsula.

The idea is to allow the shuttles to continue picking up their passengers without causing delays for the city’s public transit buses or tying up vehicular traffic in the congested Castro neighborhood.

“What we are really trying to test is does this minimize impacts on Muni and other users,” said Carli Paine, a manager with the San Francisco Municipal Transportation Agency’s Sustainable Streets Division, during this morning’s Castro Merchants meeting.

Paine’s department is proposing the SFMTA create permitted commuter shuttle only zones in the following locations in the Castro.

One would be created on the west side of Church Street at 15th Street, in front of a plumbing store and cafe, and would be used between 6 and 10 a.m.

Two would be on Castro Street. The first, on the east side of Castro Street at Market adjacent to the Pottery Barn building, would be in effect from 4 to 8 p.m.

The second zone would be on the west side of Castro Street at 18th Street in front of the Walgreens. It would be used between 6 and 10 a.m.

The SFMTA’s Sustainable Streets Division will consider the proposed three shuttle zones at its September 19 Engineering Public Hearing. The proposal will then go before the SFMTA Board for approval.

If the Church Street/15th zone is approved, then the zone currently being used in the mornings on Church Street at Market adjacent to the Safeway will be removed.

“In the Castro it has been really hard to find acceptable locations,” said Paine, noting that “there is a large population of the shuttle riders in the Castro.”

While Castro merchants welcome seeing the shuttle stops near their businesses, they are also concerned about seeing parking spaces be taken out of service, even if for a limited time.

“I am not unhappy with the shuttle buses going through the Castro, but I am worried about the loss of parking spaces,” said Hortica owner David Gray. “I love the people getting off the buses because they become my customers. But I also don’t want to lose metered parking spaces for customers.”